1

GATE ECE 2002

Subjective

+5

-0

A unity feedback system has the plant transfer function
G

(a) Determine the frequency at which the plant has a phase lah of 90

(b) An intergral controller with transfer function G

(c) Determine the steady state errors of the compensated system to unit-step and unit-ramp inputs.

_{p}(s)=$${1 \over {\left( {s + 1} \right)\left( {2s + 1} \right)}}$$(a) Determine the frequency at which the plant has a phase lah of 90

^{o}.(b) An intergral controller with transfer function G

_{c}(s)=$${k \over s}$$ , isplaced in the forwardpath the value of k such that the compensated system has an open loop gain margin of 2.5.(c) Determine the steady state errors of the compensated system to unit-step and unit-ramp inputs.

2

GATE ECE 2001

Subjective

+5

-0

For the feedback control system shown in the figure, the process transfer function is
G

(a) Find the desired location of the closed loop poles.

(b) Write down the requiredcharacteristic equation for the system. Hense determine the PD controller transfer function G

(c) Sketch the root-locus for the system.

_{p}(s) = $${1 \over {s(s + 1)}},$$ and the amplification factor of the Power amplifier is K$$ \ge $$0. The design specifications required for the system, time constant is 1 sec and a damping ratio of 0.707.(a) Find the desired location of the closed loop poles.

(b) Write down the requiredcharacteristic equation for the system. Hense determine the PD controller transfer function G

_{p}(s) when K = 1.(c) Sketch the root-locus for the system.

Questions Asked from Compensators (Marks 5)

Number in Brackets after Paper Indicates No. of Questions

GATE ECE Subjects

Network Theory

Control Systems

Electronic Devices and VLSI

Analog Circuits

Digital Circuits

Microprocessors

Signals and Systems

Representation of Continuous Time Signal Fourier Series
Fourier Transform
Continuous Time Signal Laplace Transform
Discrete Time Signal Fourier Series Fourier Transform
Discrete Fourier Transform and Fast Fourier Transform
Discrete Time Signal Z Transform
Continuous Time Linear Invariant System
Discrete Time Linear Time Invariant Systems
Transmission of Signal Through Continuous Time LTI Systems
Sampling
Transmission of Signal Through Discrete Time Lti Systems
Miscellaneous

Communications

Electromagnetics

General Aptitude